The main aim of this study was to compare the efficiency of cold and hot solvent extraction (Soxhlet method) of oil from dry matter of three types of lyophilized plant material (olive paste without kernel, olive paste with kernel, olive seeds of Leccino cultivar) and to compare the mass fraction of phenolic compounds and ortho-diphenols in so obtained oils. Also, the antioxidant capacity of plant material was determined. A short description of the laboratory methods of oil extraction, characteristics of the olives of Leccino cultivar and the determination of antioxidant capacity by the DPPH method was given. Also, structure and composition of olive fruit, olive oil processing from de-stoned fruits and characteristics of the olive fruit and oil phenol compounds, were described. In the experimental part it was showed that cold and hot extraction were equally effective in extracting oils from lyophilized olive pastes, but the hot extraction was more efficient in the oil extraction from seeds. Between olive paste processed with and without kernel, statistically significant differences were determined for: a) oil content (39% vs. 52%), b) mass fraction of total phenols (8.62 mg/g vs. 12.87 mg / g) and c) antioxidant capacity (IC50 6.33 mg/mL vs. 3.56 mg/mL). Seeds had statistically significant lower total phenols mass fraction (5.27 mg/g) and multiple higher IC50 values (46.43 mg/mL) compared to olive pastes. In oils obtained by hot extraction from the all three plant materials (both olive pastes and seed), statistically significant higher values were determined for: a) total phenols mass fraction (3 to 10 fold in regard to cold extraction), b) the ortho-diphenol mass fraction (9 fold in regard to cold extraction). These results confirm previous knowledge, that removing olive kernel reduces the negative impact of seed peroxidase on the phenolic compounds in the olive paste and oil, as well as suggest that, hot oil extraction increases solubility of phenolic compounds from plant material in oil.